Getting it into your agent
One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.
npx skills add DauQuangThanh/hanoi-rainbow --skill cobol-migration-analyzergit clone --depth 1 https://github.com/DauQuangThanh/hanoi-rainbowWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/skills/dauquangthanh/hanoi-rainbow/cobol-migration-analyzer)<a href="https://agentmods.dev/skills/dauquangthanh/hanoi-rainbow/cobol-migration-analyzer"><img src="https://agentmods.dev/badge/skills/dauquangthanh/hanoi-rainbow/cobol-migration-analyzer/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/skills/dauquangthanh/hanoi-rainbow/cobol-migration-analyzer"><img src="https://agentmods.dev/badge/skills/dauquangthanh/hanoi-rainbow/cobol-migration-analyzer.svg" alt="Reviewed on agentmods" width="80" height="20"></a>What it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00102 | $0.01952 |
| Opus 5.5 | $0.00041 | $0.00781 |
| Sonnet 5.5 | $0.00020 | $0.00390 |
| Haiku 4.5 | $0.00010 | $0.00195 |
Grade A, and why
cobol-migration-analyzer scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 1mo ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
How it starts
The opening of the file, as written. The whole thing — 168 lines — stays where its author put it; the contents beside it link to each section on GitHub.
COBOL Migration Analyzer
Analyze legacy COBOL programs and JCL scripts for migration to Java. Extract business logic, data structures, and dependencies to generate actionable migration strategies.
Core Capabilities
1. COBOL Program Analysis
Extract COBOL divisions (IDENTIFICATION, ENVIRONMENT, DATA, PROCEDURE), Working-Storage variables, file definitions (FD), business logic paragraphs, PERFORM statements, CALL hierarchies, embedded SQL, and error handling patterns.
2. JCL Job Analysis
Parse JCL job steps, program invocations, data dependencies (DD statements), conditional logic (COND, IF/THEN/ELSE), return codes, and resource requirements.
3. Copybook Processing
Extract record layouts with level numbers, REDEFINES clauses, group items, OCCURS clauses, and picture clauses. Generate Java POJOs from copybook structures.
4. Dependency Mapping
Build complete dependency graphs showing CALL hierarchies, copybook usage, file dependencies, database table access, and shared utility references across the codebase.
Workflow
Step 1: Discover COBOL Assets
Find COBOL programs, JCL jobs, and copybooks:
find . -name "*.cbl" -o -name "*.CBL" -o -name "*.cob"
find . -name "*.jcl" -o -name "*.JCL"
find . -name "*.cpy" -o -name "*.CPY"
Use scripts/analyze-dependencies.sh or scripts/analyze-dependencies.ps1 to generate dependency graph.
Step 2: Extract Structure
Use scripts/extract-structure.py to parse COBOL programs and extract divisions, variables, paragraphs, and dependencies in JSON format.
Step 3: Generate Java Code
Use scripts/generate-java-classes.py to convert copybooks to Java POJOs with appropriate data types and Bean Validation annotations.
Step 4: Estimate Complexity
Use scripts/estimate-complexity.py to calculate migration complexity based on LOC, external calls, file operations, SQL statements, and control flow.
Step 5: Create Migration Strategy
Document program overview, dependencies, data structures, business logic patterns, proposed Java design, migration estimate, and action items.
What ships with it
13 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.
- assets/java-class-template.java 2.3 KB
- assets/migration-report-template.md 5.0 KB
- references/messaging-integration.md 11 KB
- references/performance-patterns.md 5.8 KB
- references/pseudocode-cobol-rules.md 11 KB
- references/pseudocode-common-rules.md 2.3 KB
- references/testing-strategy.md 13 KB
- references/transaction-handling.md 11 KB
- scripts/analyze-dependencies.ps1 5.1 KB runs code
- scripts/analyze-dependencies.sh 5.1 KB runs code
- scripts/estimate-complexity.py 8.2 KB runs code
- scripts/extract-structure.py 7.1 KB runs code
- scripts/generate-java-classes.py 9.3 KB runs code
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- 1mo ago First seen · 168 lines · 102 tokens per session scan A 355a3c96e69e
cobol-migration-analyzer is a skill published in the GitHub repository DauQuangThanh/hanoi-rainbow (17 stars, last pushed 9mo ago), licensed MIT. It adds 102 tokens to every session and 1,952 once invoked, about $0.0004 per session on Opus 5.5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.
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